Scrape, scratch, grate, rasp, grind are comparable when they mean to apply friction to something by rubbing it with or against a thing that is harsh, rough, or sharp.
Scrape usually implies the removal of something from a surface with an edged instrument; the term then commonly suggests a purpose (as erasing, smoothing, or freeing from dirt, paint, skin, or peel).
Additionally the term commonly implies the making of a distinctive and often unpleasant sound.
Scratch differs from scrape in its common implication of less purposiveness in the agent and of definite damage to the thing that is scratched; it usually also suggests the use of a pointed rather than an edged instrument which gouges a line or furrow in a surface and seldom stresses the noise produced.
Grate usually stresses the harsh sound or the sensation of harshness made by rubbing something with or against a rough indented or cutting surface (as of a file); the term implies removal of material from a body in particles, and in itself as distinct from context suggests nothing about the aims or effects (as abrasion, wearing or rubbing away, or pulverization).
Often grate implies little more than a harsh or creaking sound made by friction. In extended use the term tends to be used in reference to things that irritate, exasperate, or harass with the implication that their effect is like the harsh sound or the sensation of harshness characteristic of a physical grating.
Rasp usually implies a harsher or rougher and more disagreeable effect than either scrape or grate. It may suggest the use of or as if of a rough instrument (as a coarse file called a rasp ) or of something equally effective or as trying to the nerves.
Grind implies a sharpening of the edge or point of a tool or weapon or the smoothing of a surface (as of glass) by friction; in both uses the sound made in the act of grinding is often stressed.
In extended use the word often implies a wearing down by friction and also often suggests a particularly harsh or rough method of gaining one’s ends or of making one’s way.